Nam Dong, a mountainous district in central Vietnam, is located in a fragile natural resource area and therefore must be conserved. Agricultural productions, especially, cultivation systems played important role as livelihoods for local people, but its development trend was spontaneous in this region. Therefore, how to develop its potential with trade-off between productivity and sustainability had become an important issue for stakeholders. Nevertheless, researches about crop production systems (CPSs) under sustainable trends still had not adequately considered yet. Thus, this study was conducted aiming at providing information as well as evaluating and comparing the sustainability of CPSs at the household level in each micro-zone of this district. In such situation, the methods of Analytic Hierarchy Process (AHP) and Sustainability Indicator Analysis (SIA) were particularly applied with seven selected indicators representing ecological, economic, and social dimensions. From the results of interviews in three selected study areas in Nam Dong, it was found that six main CPSs were applied in the district. However, in each particular commune, farmers applied different CPSs, land use patterns, cropping patterns, as well as other farming technical practices. Therefore, they got different profitability and yield stability. The significance of each indicator and overall aspect in sustainability of CPSs were outlined through the methods explained above. CPSs recommended in Huong Loc and Thuong Quang communes were Industrial Annual Crop and Vegetable along Stream, respectively. Meanwhile, Industrial Annual Crop and Fruit-Industrial Perennial Crop were recommended in Huong Phu commune by the SIA and AHP methods, respectively. However, regarding the environment in farming practices, it needs to be improved and concerned for both promising CPSs and disadvantageous CPSs. Proper conservations of soil fertility and advanced technique applications were required, since the yield stability of CPSs showed high fluctuations. In addition, the decision-making for choosing suitable practices should consider both natural and socio-economic characteristics of the local context.

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Cattle grazing in abandoned fields has recently been of great importance in promoting effective utilization of local resources in Japan. The objectives of this study were to investigate spatial distributions of grazing cattle in abandoned fields and to analyze relationships between the patterns of spatial distribution and energy expenditure (EE) of the grazing cattle using global positioning system (GPS) and geographic information system (GIS). GPS collars were attached to 2 Japanese Black cows and their positional records with an interval of 5 minutes were collected during 3 seasons throughout 2008; June, September, and October. Using GIS, a 3D map of the study area was derived from a digitized contour map and the slope gradient of each pixel was calculated. Utilization distributions of grazing cattle were estimated by fixed kernel method using GPS records. Three levels of intensity utilization areas (high, middle and low) were estimated from the utilization distributions and thereby their sizes and average slope gradients (ASG) were calculated. EEs of grazing cattle were estimated from walking speeds and walking slope gradients calculated from GPS records. Results showed that ASGs of high and middle intensity utilization areas in October were significantly steeper (P<0.05) than those in June. Sizes of all the intensity utilization areas in daytime (from sunrise to sunset) were significantly larger (P<0.01) than those in nighttime (from sunset to sunrise following morning). ASGs of all the intensity utilization areas in daytime were significantly gentler (P<0.01) than those in nighttime. ASGs of all the intensity utilization areas in both daytime and nighttime were positively correlated with EEs in June. Although sizes of high and middle intensity utilization areas exhibited negative correlations with EE in September, they were positively correlated with EE in October.

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We investigated the estimation of the inorganic nitrogen concentration (INC) in irrigation water using electrical conductivity (EC) measurements for its application to fertilizer management in rice production. Data on the INC and EC of irrigation water were collected throughout the rice growth seasons of 2008 and 2009 from five water systems located in Hoshino Village, Fukuoka Prefecture, Japan, and the relationship between the INC and EC was investigated using linear regression analysis. In addition, ion balances were calculated for two water systems (i.e., Hirouchi and Rokuri) where high INC was detected in order to clarify the factors affecting the linear relationship between the INC and EC. Further, the equations used to estimate the INC were derived individually for each water sampling date; the stability of these equations was examined in terms of the variations in the equations' slopes and intercepts, and the accuracy of each equation was evaluated by using mean relative error of cross validation (MRECV) and the standard deviation of relative error (SDRE). The results obtained in this study were as follows: (1) It is difficult to estimate the INC by measuring the EC in water systems in which the INC is less than 3 mg/L because the dissolved ions except those of inorganic nitrogen cause large variations in the EC. (2) Because irrigation water exhibits characteristic ion balances that are affected by fertilizer management in a watershed, it is appropriate to derive the equations used to estimate the INC individually for each water system. (3) It must be taken into account that the equations used to estimate the INC can become unstable when the data employed for deriving the equations are collected at the sampling points where changes in fertilizer management easily affect the quality of irrigation water. (4) The MRECV ranged from 18 to 25% in the Hirouchi water system and from 13 to 18% in the Rokuri water system, and the SDRE ranged from 15 to 20% and from 13 to 15%, respectively, when the INC was higher than 5 mg/L. If the accuracy evaluated in this study is taken into account, then for conditions of high INC, the INC values estimated using EC measurements can be considered as useful indicators of nitrogen supply from irrigation water.

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The purpose of this research is to figure out the nationwide trend of agricultural nonprofit organizations (NPOs) and their activities throughout the country. The NPOs database showed that there are 943 agricultural NPOs in Japan until May 2008. This is 2.7% of the total numbers of NPOs 035,544). Agricultural NPOs are engaged in various kinds of activities such as, research, proposal and education (34.8%), agricultural support (31.4%), interaction between urban and rural areas (29.6%), farmland, forest and water (28.6%) and sustainable agriculture (21.6%). On the other hand, fewer agricultural organizations are engaged in organic certification (2.8%), cultural property (3.8%) and new farmer support (9.0%). 47.3% agricultural NPOs have an annual income of less than ¥1,000,000 and most of the NPOs have an annual income of less than ¥5,000,000 (72.6%). In comparison with all kinds of NPOs working in the country, agricultural NPOs can be considered as a group with less annual income. As for geographical distribution, 36% of the agricultural NPOs exist within 10km from their prefectural capitals. Furthermore, those within 30km account for approximately 60%. These results imply that most agricultural NPOs exist in and near urban areas, and fewer exist in rural areas.

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